With the increase of network distribution of operating systems (OSs), operating system vendors (OSVs) (e.g., Redhat Linux or Microsoft) aspire to, in concert with the original equipment manufacturers (OEM) (e.g., Dell or Hewlett-Packard) manage licensing, subscription, boot policy, and expiry of the operating systems on their platforms.
However, a problem with such an approach is that true licensing and control of OS booting and installation is difficult to perform safely from within the OS. For instance, during a system restart, the OS may be attacked via root-kits, viruses, and other malicious content.